Preparation

1. Line a fine-mesh strainer with a triple layer of coffee filters and set it over a liquid measuring cup. Spoon the yogurt into the strainer, cover with plastic wrap, and refrigerate until the yogurt has released 59 ml (¼ cup) of liquid, about 2 hours.

2. Place the jalapenos, garlic, sugar, and salt in a food processor, and process until the chiles are finely chopped. Stop to scrape the sides of the bowl as needed. Add the drained yogurt whey and pulse to combine.

3. Transfer the mixture to a 1 liter (1 quart) glass jar and cover with a kitchen towel or triple layer of cheesecloth. Secure the towel with a rubber band. Let the chile mixture sit at room temperature to ferment until bubbles have formed in the mixture and the chile mixture has risen and then fallen (indicating that fermentation has slowed down), around 12 to 16 days.

4. Transfer the chile mixture to the jar of a blender, add the white vinegar, and puree until completely smooth, 1 to 3 minutes. Transfer to a medium-mesh strainer set over a medium saucepan. Strain the chile mixture into the saucepan, using a rubber spatula to push through as much pulp as you can. You’ll want to leave behind only the seeds and large pieces of chiles behind.

5. Bring the mixture to a boil over medium-high heat. Reduce the heat to medium-low and simmer until the sauce thickens enough to cling to a spoon, about 15 minutes. Transfer to glass jar or plastic squeeze bottle and store in the refrigerator for up to 6 months.